Free Expert Guides on Power Systems, Circuit Design & Electrical Troubleshooting

Eco-friendly gas-insulated ring main units (RMUs) are important power distribution equipment in electrical systems, featuring green, environmentally friendly, and high-reliability characteristics. During operation, arc formation and interruption characteristics significantly affect the safety of eco-friendly gas-insulated RMUs. Therefore, in-depth research on these aspects is of great significance for ensuring the safe and stable operation of power systems. This article aims to investigate the a

From the perspective of insulation performance, sulfur hexafluoride SF6 exhibits excellent insulating properties. Its dielectric strength is approximately 2.5 times that of air, effectively ensuring the insulation performance of electrical equipment under standard atmospheric pressure and ambient temperature. The new SF6 gas free gases used in SF6 gas-free switchgear—such as certain gas mixtures—can also meet insulation requirements, though their specific values vary depending on the formulation

(1) The contact gap is primarily determined by insulation coordination parameters, interruption parameters, contact material of the high-voltage SF₆-free ring main unit, and the design of the magnetic blowout chamber. In practical application, a larger contact gap is not necessarily better; instead, the contact gap should be adjusted as close as possible to its lower limit to reduce operating energy consumption and extend service life.(2) The determination of contact overtravel is related to fac

Insulation degradation in power equipment is generally caused by multiple factors. During operation, insulation materials (such as epoxy resin and cable terminations) gradually deteriorate due to thermal, electrical, and mechanical stresses, leading to the formation of voids or cracks. Alternatively, contamination and moisture—such as dust or salt deposition or high-humidity environments—can increase surface conductivity, triggering corona discharge or surface tracking. Additionally, lightning s

Intelligent complete sets of electrical switchgear and intelligent controller products are essential components in the manufacturing of intelligent ring main units (RMUs). The intelligent integration of complete switchgear combines advanced manufacturing technologies with information technology, effectively enhancing the power grid’s capabilities in state awareness, data analysis, decision-making, control, and learning, thereby fully embodying the digital, networked, and intelligent development

1. Regarding GIS, how should the requirement in Clause 14.1.1.4 of the State Grid’s "Eighteen Anti-Accident Measures" (2018 Edition) be understood?14.1.1.4: The neutral point of a transformer shall be connected to two different sides of the main mesh of the grounding grid via two grounding down conductors, and each grounding down conductor shall meet the thermal stability verification requirements. Main equipment and equipment structures shall each have two grounding down conductors connected to

1. Key Points for Debugging High-Voltage Power Distribution Cabinets in Power Systems1.1 Voltage ControlDuring the debugging of high-voltage power distribution cabinets, voltage and dielectric loss show an inverse relationship. Insufficient detection accuracy and large voltage errors will lead to increased dielectric loss, higher resistance, and leakage. Therefore, it is necessary to strictly control the resistance under low-voltage conditions, analyze current and resistance values, and avoid ex

Recently, a ±550 kV DC GIS (Gas-Insulated Switchgear), jointly developed by a Chinese GIS manufacturer and multiple companies, successfully completed a 180-day outdoor long-term energized reliability test at the Xi’an High Voltage Apparatus Research Institute. This marks the first time in the industry that a next-generation ±550 kV DC GIS has passed such a long-term energized evaluation.The ±550 kV DC GIS had already undergone comprehensive performance verification tests at the Xi’an High Voltag

With the implementation of the EU’s new F-Gas Regulation (Regulation (EU) 2024/573), the power equipment industry is entering a countdown toward environmental transformation. The regulation explicitly prohibits, starting in 2026, the use of fluorinated greenhouse gases in medium-voltage switchgear rated at 24 kV and below. This restriction will be extended to equipment up to 52 kV from 2030 onward, accelerating the industry’s shift away from sulfur hexafluoride (SF₆)—a gas with a high global war

On October 16, a ±800 kV ultra-high-voltage (UHV) transmission project completed all its maintenance tasks and was fully re-energized. During this period, a regional power company successfully conducted the first-ever fully unmanned inspection of the GIS (Gas-Insulated Switchgear) room at a UHV converter station within this power system.As a key component of China’s “West-to-East Power Transmission” strategy, the ±800 kV UHV project has been in operation since 2016 and has delivered nearly 400 b